SNAPSHOT: Imaging the Brain

Scientists and doctors have a varied set of tools they use to image the brain, and each tool comes with trade-offs. Techniques like functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and electrocorticography (ECoG) all help researchers map brain activity. But they do so in different ways, with differing strengths and weaknesses.

Direct comparisons between methods can help scientists decide which method to use in a study, or whether they can swap out one technique for another.

In a study that appears in the journal NeuroImage, researchers imaged the brains of subjects using three different techniques. The study compared the results of fMRI and EEG, and used ECoG results as a “gold standard.” The subjects all watched the same clip from the Al Pacino drama Dog Day Afternoon, letting the scientists compare responses to the same stimulus as imaged by three methods.

A movie clip, the researchers said, is a more natural, lifelike stimulus than the noises and flashes often used in imaging studies, making their results applicable to a wider variety of imaging situations.

“We found that the two modalities, fMRI and EEG, correlated in some regards,” said Professor Lucas Parra of The City College of New York and The Graduate Center, an author on the study. “But we also found that they capture genuinely different information, so one cannot really be used as a substitute for the other.”